When you say that something is a good, it is because the good is what is sought when achieving an end. All voluntary actions are taken to achieve something that is considered to be a good on some level by oneself, thus it is impossible to seek evil in and of itself unless one is insane and views evil itself as a good. It is possible to seek goods that are lesser, detrimental to others, or based on an inaccurate understanding of reality--this is corruption.

My point is that people do not seek to do evil ever, they only seek to do things that are good only for themselves and no one else, or they are deluded as to the reality of a situation. Even people who perversely seek to do acts of pure malice view the pleasure obtained from the malicious act to be a good that is sought by themselves. What we call evil is the choosing of a lesser good over a greater one, so there is a hierarchy of goods, with the best action being at the top and the worst action being the least good. Evil is like an asymptote that can't ever be reached. Pure Evil is like the speed of light: it can be sought, but never obtained, and this is because one simply seeks evil as a good, leaving the tiniest spark of goodness in one's motivations.

There is always some good sought for someone or something in some action, so one should speak about what is the best course of action to achieve worthy goals, acknowledging the hierarchical nature of goods and their complex relationships to people and things rather than fitting them into a binary category. Binaries do not exist in nature, they are a product of simplified human analysis of a situation. What does exist in reality is a complex set of interacting things, and goodness is what one seeks when one performs literally any action--even if it is an inferior good that is accompanied by great destructiveness to others or the world.